5 Ideas for Doubling the World's Food Supply

There has been some fascinating research on how sustainable farming methods -- mainly organic and agroecological farming -- can increase crop yields. Conventional -- also called "industrial" -- farming methods rely heavily on synthetic inputs, like fertilizers and pesticides. In the short term, this increases yields, but over time, it harms soil health and even contributes to the growth of "superweeds" -- weeds that are resistant to pesticides. Sustainable farming focuses on soil health and natural pest control, rather than synthetic chemicals.

Rachel Shulman, owner of River Run Farm in Illinois, talked about her organic farm with me and how industrial farms, both conventional and organic, could take a page from small-scale organic farming to increase yields. For example, Shulman advocates spraying pesticides as-needed, rather than preventively. Overuse of pesticides is bad for the soil and bad for crops in the long term.

Shulman says focusing on soil health is the number one way to increase yields, and recent studies seem to back that up. One study in Africa is using long-term meteorological data to predict soil moisture to help farmers increase yields, and USDA chief meteorologist Ray Motha says this approach could double Africa's food production in just 10 years [source: George Mason University]. The U.N. got similar positive results working with small-scale farmers in Africa. Using agroecological methods, they saw crop yields increase 116 percent [source: Norström].

Organic farming has also seen some impressive results when it comes to increasing yields. A report from the Worldwatch Institute looked at long-term research on organic farming methods that focus on improving soil health, and found that organic farms yielded almost the same amount of food as conventional farms in wealthy countries and up to 20 percent more food in developing countries [source: Halwell].

Wealthier farmers did see a drop in yields when first switching to organic farming [source: Halwell]. The cause for that drop is also the main challenge that sustainable farmers face: The soil needs time to recover from years of chemical pesticides and fertilizers. Farmers may not want to -- or be able to -- cope with lost income as their land recovers.

What we grow is as important as how we grow it, and some researchers are looking to hardier food crops and biodiversity as a solution to help increase yields. Our industrial food system focuses on what's called monocropping, which means that farmers plant the same crops on the same land year after year. Monocropping means less biodiversity in the field, which over time is bad for yields. A large-scale 2009 study in China found a 33.2 to 84.7 percent increase in production when farmers grew a mix of crops in their fields, rather than focusing on just one [source: Li].

Some experts advocate a switch from annual crops to perennial. Annual crops like corn need to be re-planted year after year, but perennials come back without replanting. As Shulman points out, that makes them hardy, so they use less fertilizer and less water. These types of plants are also more resilient to environmental changes, like a super hot summer. The extreme summer drought of 2012 destroyed the corn crop, but perennial grains didn't have this problem.

The Land Institute -- a Kansas-based research entity on food -- suggests that a switch to perennial grains could also help increase yield by making crops more weather-resistant, using less water, and reducing soil erosion, thanks to their deeper roots [source: Kunzig]. Perennial hybrids, like wheat-wheatgrass, are hardier and use less water and can be made into flour, just like the annual wheat we're used to seeing in fields now.

So, why aren't we growing more perennial crops and focusing on biodiversity in our farming on a larger scale? Our food system is pretty entrenched in a monocropping system. Farmers who have been growing corn year after year for decades may not be keen on growing varieties of food or on growing something new. Some crops receive government subsidies while others don't. There also hasn't been enough research on perennials to convince farmers to make the switch [source: Kunzig].

If we're going to feed 9 billion people, we need to grow food in more places. Urban farming takes advantage of unused and blighted urban areas to grow food. With more than half of the world population now living in urban areas, it makes sense to start growing food where more and more people are living [source: Southern Innovator].

In Cuba, for example, urban farming has transformed city areas, creating jobs, and producing most of the vegetables that the people in its cities consume [source: Southern Innovator]. Cities like Havana saw an explosion in urban farming in the '90s, when the collapse of the Soviet Union made fuel prohibitively expensive. People in Havana had to stop relying on food from far-off farms and growing food in the city where they lived. Today, urban farmers cultivate almost 90,000 acres (35,000 hectares) of vegetables in Havana alone [source: Koont].

In the U.S., Detroit is seeing an urban farming renaissance. As the city's economy has declined, there have been more and more vacant lots and abandoned properties. Detroit urbanites are transforming those blighted areas into thriving city farms to feed themselves and poor people in the city [source: McIntire-Strasburg].

Not all cities have huge expanses of vacant land, and that's where vertical farming comes in. Vertical farming refers to growing food on rooftops and even on walls, using vertical space to grow more food with less acreage. In Vancouver, Alterrus Systems is converting a parking garage into a lettuce farm, for example [source: Fong].

Urban farming is often small-scale, so it can help us produce more food, but needs massive buy-in from city-dwellers to make a larger impact. Not all cities make urban farming easy, either. In Drummond, Quebec, a new ordnance decrees that only 30 percent of a garden can be given over to vegetables [source: Grist].

The U.S. wastes 40 percent of the food produced, through factors such as crop spoilage, storage spoilage and consumers throwing out food that has gone bad [source: McIntire-Strasburg]. If we can cut that number down, it's the same as increasing yields.

Our food system is not always efficient. India's 2012 grain shortage is a prime example. In the summer of 2012, almost non-existent distribution, grain subsidies and lack of proper storage meant that grains rotted in the field while poor families in India starved [source: Bhardwaj]. The developing world isn't the only place where systemic problems mean wasted food. A shortage of apple pickers in the fall of 2012 meant that apples rotted on the vine in Washington state [source: King].

On the industrial agricultural level, the U.S. is making baby steps -- in one case, baby carrot steps to reduce waste. Those convenient baby carrots that are so good dipped in hummus are not actually young carrots but irregular carrots: ones that don't meet the high aesthetic standards at the grocery store. Producers reshape them into smaller, bite-sized carrots so that those veggies don't go to waste [source: Gunders]. Ugly produce is often just as safe to eat as pretty produce, but grocers won't stock ugly veggies for fear that consumers won't buy them.

Some companies, like Stop and Shop, are also learning that reducing food waste means saving money. By looking at what perishable foods their stores were wasting, Stop and Shop has saved $100 million per year [source: Gunders].

On the consumer side, education programs can help stem food waste. The U.K. runs a Love Food Hate Waste program aimed at teaching consumers how to waste less food at home. Individuals and families can take mindful steps to reducing waste, like planning meals and cooking leftovers. Proper storage can help reduce food waste too. The Web site Food Republic has an excellent infographic showing where to store different sorts of food in the refrigerator to make them last longer.

Livestock farming is terribly inefficient, whether you're raising animals for their meat or the food they produce, like eggs or milk. Rather than feeding grains to hungry people, we feed them to animals to produce meat, eggs and dairy products. It takes more than 30 pounds (13.6 kilograms) of corn to produce a single pound of meat, and cutting out that "middleman" is effectively increasing yield, since it means more calories going directly to hungry mouths [source: Fromartz].

Developing countries like China are eating more meat, which means our global food system is getting less efficient by the day. In China, the main grain that people eat is rice, but Chinese farmers are actually growing more corn for livestock than they are rice for people right now [source: Earth Policy Institute].

The United Nations even recommends shifting to a more plant-based diet to help combat world hunger. Animal agriculture accounts for 50 percent of water use worldwide [source: Oppenlander]. Not only is raising plant foods more efficient, but animal agriculture's environmental impacts are contributing to climate change, which will make it harder to grow food in the future [source: Carus].

However, people love meat and eggs, and they love cheese. As with reducing food waste, it's hard to show consumers a personal benefit to giving up something they enjoy to help people they've never met, but some scientists say that water shortages and a growing population will force all of us to eat about 75 percent less meat in the next 40 years as raising animals for meat and meat byproducts will become more and more expensive [source: Vidal].

There is no silver bullet to our worldwide food problems, but focusing on increasing efficiency and yields while reducing waste and the environmental impacts of food production are going to be the keys to feeding 9 billion people by 2050.